Impedance matching integrous signal combiner

ABSTRACT

A front-end module (FEM) is disclosed that includes an integrous signal combiner. The integrous signal combiner can process received signals and use a set of resonant circuits to filter signal noise prior to recombination of a plurality of signal bands that form an aggregate carrier signal. These resonant circuits may be placed after a set of low noise amplifiers and can be used to more efficiently reduce noise and parasitic loading within each of a set of signal paths. Each resonant circuit may be configured to filter noise relating to a bandwidth for a signal that is to be combined with the signal of the signal path that includes the resonant circuit. The signals may be combined using a dynamic impedance matching circuit. In some implementations, the integrous signal combiner can be a tunable integrous signal combiner with resonant circuits that may be reconfigurable or dynamically configurable.

RELATED APPLICATIONS

This disclosure claims priority to U.S. Provisional Application No.62/167,516, which was filed on May 28, 2015 and is titled “MULTIBANDSIGNAL AGGREGATION,” the disclosure of which is expressly incorporatedby reference herein in its entirety for all purposes. Further, thisapplication is related to U.S. Application No. 15/166,930, which wasfiled on May 27, 2016 and is titled “INTEGROUS SIGNAL COMBINER,” thedisclosure of which is expressly incorporated by reference herein in itsentirety for all purposes.

BACKGROUND

Technical Field

This disclosure relates to carrier aggregation and, in particular, toprocessing received multiband signals.

Description of Related Technology

Often, wireless communication involves sending and receiving signalsalong a particular communication band. However, in some cases, wirelesscommunication may involve the use of multiple communication bands, whichis sometimes referred to as multiband communication and may involvemultiband signal processing. Usually, when a wireless device receives amultiband signal, the wireless device will perform carrier aggregationto aggregate the constituent signals. This can result in a widerbandwidth and it can be possible to receive data or communicationsignals at a higher data rate.

BRIEF DESCRIPTION OF THE DRAWINGS

Throughout the drawings, reference numbers are re-used to indicatecorrespondence between referenced elements. The drawings are provided toillustrate embodiments of the inventive subject matter described hereinand not to limit the scope thereof.

FIG. 1A is a block diagram of one example of a wireless device thatincludes a front end module.

FIG. 1B is a block diagram of one example of the wireless device of FIG.1A in communication with a base station.

FIG. 2A is a block diagram of one example of the front end module thatcan be included in the wireless device of FIG. 1A.

FIG. 2B is a block diagram of a portion of the front-end module of FIG.2A.

FIG. 3 is a block diagram of another example of the front end modulethat can be included in the wireless device of FIG. 1A.

FIGS. 4A-4D are circuit schematics of examples of resonant circuits thatcan be included in the front end modules of FIGS. 2A and 3.

FIGS. 5A-5D graphically illustrate simulations of a resonant circuit fordifferent bands of operation.

FIG. 6 is a circuit schematic of one example of the front end modulethat can be included in the wireless device of FIG. 1A.

FIGS. 7A and 7B graphically illustrate simulations of Gain and NoiseFigure for the circuit schematic of FIG. 6.

FIG. 8 is a flowchart of one example of a multiband signal processingprocess for performing signal aggregation.

SUMMARY

The systems, methods and devices of this disclosure each have severalinnovative aspects, no single one of which is solely responsible for theall of the desirable attributes disclosed herein. Details of one or moreimplementations of the subject matter described in this specificationare set forth in the accompanying drawings and the description below.

Certain aspects of the present disclosure relate to a method ofprocessing a multiband signal. The method may include receiving amultiband signal at an antenna of a wireless device. Further, themultiband signal may include at least a first signal of a firstbandwidth and a second signal of a second bandwidth. In addition, themethod may include amplifying the first signal to obtain a firstamplified signal and filtering noise from the first amplified signalbased on the second bandwidth to obtain a first filtered amplifiedsignal. The method may further include amplifying the second signal toobtain a second amplified signal and filtering noise from the secondamplified signal based on the first bandwidth to obtain a secondfiltered amplified signal. In addition, the method may include combiningthe first filtered amplified signal and the second filtered amplifiedsignal.

In some embodiments, the method further includes configuring a firstresonant circuit to filter the noise associated with the secondbandwidth from the first amplified signal. Further, configuring thefirst resonant circuit may include configuring a set of switchedcapacitors based on the second bandwidth. In some cases, the methodfurther includes configuring a second resonant circuit to filter thenoise associated with the first bandwidth from the second amplifiedsignal. In some cases, the first signal is amplified using a first lownoise amplifier (LNA) and the second signal is amplified using a secondLNA.

Certain additional aspects of the present disclosure relate to anintegrous signal combiner. The integrous signal combiner may include afirst low noise amplifier (LNA) configured to process a first receivesignal of a first bandwidth to obtain a first amplified receive signal.Further, the integrous signal combiner may include a second LNAconfigured to process a second receive signal of a second bandwidth toobtain a second amplified receive signal. In addition, the integroussignal combiner may include a first resonant circuit in electricalcommunication with the first LNA. The first resonant circuit may beconfigurable to filter noise within the first amplified receive signalcorresponding to at least the second bandwidth. Moreover, the integroussignal combiner may include a second resonant circuit in electricalcommunication with the second LNA. The second resonant circuit may beconfigurable to filter noise within the second amplified receive signalcorresponding to at least the first bandwidth.

With some implementations, the first resonant circuit is furtherconfigurable to operate in a bypass mode. Moreover, the integrous signalcombiner may further include a combiner configured to combine at leastthe first amplified receive signal and the second amplified receivesignal. In addition, the integrous signal combiner may include animpedance matching network configured to match the impedance of at leastthe first resonant circuit and the second resonant circuit. Furthermore,the impedance matching network may combine at least the first amplifiedreceive signal and the second amplified receive signal.

In some embodiments, the integrous signal combiner may include a thirdLNA configured to process a third receive signal of a third bandwidth toobtain a third amplified receive signal. Furthermore, the integroussignal combiner may include a third resonant circuit in electricalcommunication with the third LNA. The third resonant circuit may beconfigurable to filter noise within the third amplified receive signalcorresponding to at least one of the first bandwidth or the secondbandwidth. In some cases, the third LNA is not in electricalcommunication with a resonant circuit. Moreover, in some cases, thethird LNA is further configured to provide the third amplified receivesignal to a transceiver without filtering noise within the thirdamplified receive signal corresponding to at least one of the firstbandwidth or the second bandwidth. In some cases, at least one of thefirst LNA, the second LNA, or the third LNA is configured to be inactivewhile at least one other LNA of the first LNA, the second LNA, or thethird LNA is configured to be active.

In certain implementations, the first resonant circuit includes a firstfilter and the second resonant circuit includes a second filter.Further, the first resonant circuit may include a first set of switchedcapacitors and the second resonant circuit may include a second set ofswitched capacitors.

Some other aspects of the present disclosure relate to a front-endmodule (FEM). The FEM may include an integrous signal combiner and animpedance matching network. The integrous signal combiner may include afirst low noise amplifier (LNA) configured to process a first receivesignal of a first bandwidth to obtain a first amplified receive signaland a second LNA configured to process a second receive signal of asecond bandwidth to obtain a second amplified receive signal. Further,the integrous signal combiner may include a first resonant circuit inelectrical communication with the first LNA. The first resonant circuitmay be configurable to filter noise within the first amplified receivesignal corresponding to at least the second bandwidth. In addition, theintegrous signal combiner may include a second resonant circuit inelectrical communication with the second LNA. The second resonantcircuit may be configurable to filter noise within the second amplifiedreceive signal corresponding to at least the first bandwidth. Moreover,the impedance matching network may be in communication with theintegrous signal combiner and may be configured to match the impedanceof at least the first resonant circuit and the second resonant circuit.

In certain embodiments, the impedance matching network is furtherconfigured to combine at least the first amplified signal and the secondamplified signal. Further, the first resonant circuit may be furtherconfigurable to operate in a bypass mode. In addition, the firstresonant circuit may include at least one configurable element enablingthe integrous signal combiner to be dynamically tuned.

Additional aspects of the present disclosure relate to a wireless devicethat includes an antenna and a front-end module. The antenna may beconfigured to receive a multiband signal including at least a firstsignal of a first bandwidth and a second signal of a second bandwidth.Further, the FEM may be in electrical communication with the antenna andmay include an integrous signal combiner. The integrous signal combinermay include a first low noise amplifier (LNA), a second LNA, a firstresonant circuit in electrical communication with the first LNA, and asecond resonant circuit in electrical communication with the second LNA.The first LNA may be configured to process the first signal to obtain afirst amplified signal. In addition, the second LNA may be configured toprocess the second signal to obtain a second amplified signal. The firstresonant circuit may be configurable to filter noise within the firstamplified signal corresponding to at least the second bandwidth and thesecond resonant circuit may be configurable to filter noise within thesecond amplified signal corresponding to at least the first bandwidth.

In certain implementations, the first resonant circuit is furtherconfigurable to operate in a bypass mode. Moreover, the integrous signalcombiner may further include a combiner configured to combine at leastthe first amplified signal and the second amplified signal. In addition,in certain embodiments, the integrous signal combiner may include amatching impedance network configured to match the impedance of at leastthe first resonant circuit and the second resonant circuit. Further, theimpedance matching circuit may combine at least the first amplifiedsignal and the second amplified signal.

In some embodiments, the multiband signal further includes a thirdsignal of a third bandwidth and the integrous signal combiner furtherincludes a third LNA configured to process the third signal to obtain athird amplified signal. The integrous signal combiner may furtherinclude a third resonant circuit in electrical communication with thethird LNA. The third resonant circuit may be configurable to filternoise within the third amplified signal corresponding to at least one ofthe first bandwidth or the second bandwidth. Moreover, the wirelessdevice may further include a transceiver in electrical communicationwith the FEM. In some such embodiments, the third LNA is furtherconfigured to provide the third amplified signal to the transceiverwithout noise within the third amplified signal corresponding to atleast one of the first bandwidth or the second bandwidth being filtered.In certain embodiments, at least one of the first LNA, the second LNA,or the third LNA is configured to be inactive while at least one otherLNA of the first LNA, the second LNA, or the third LNA is configured tobe active. Moreover, the first resonant circuit may include a first setof switched capacitors and the second resonant circuit includes a secondset of switched capacitors.

Certain aspects of the present disclosure relate to an integrous signalcombiner. The integrous signal combiner may include a plurality ofinputs with each input configured to receive a signal of a differentfrequency than the other inputs of the plurality of inputs. Further, theintegrous signal combiner may include an output configured to provide anintegrous signal to a subsequent processing block. In addition, theintegrous signal combiner may include a plurality of low noiseamplifiers (LNAs) and a plurality of resonant circuits. In someimplementations, each resonant circuit corresponds to a different LNAfrom the plurality of LNAs.

In some embodiments, the subsequent processing block is a transceiver.Further, in certain designs, the integrous signal combiner includes acombiner configured to combine a plurality of integrous signals. Each,or at least some, of the integrous signals from the plurality ofintegrous signals may be output by a different resonant circuit from theplurality of resonant circuits. In some cases, the integrous signal is acombined signal created from a plurality of communication bands. Inother cases, the integrous signal is formed from a single communicationband.

With some embodiments, at least one resonant circuit from the pluralityof resonant circuits includes a switch that when closed causes the atleast one resonant circuit to be bypassed. Moreover, in certainimplementations, the integrous signal combiner includes a switch betweenan LNA from the plurality of LNAs and a corresponding resonant circuitfrom the plurality of resonant circuits. This switch may be configuredto switch between the corresponding resonant circuit and a bypass paththat bypasses the corresponding resonant circuit. Furthermore, at leastone resonant circuit from the plurality of resonant circuits may includea switched capacitor enabling the at least one resonant circuit to bedynamically adjusted.

Other aspects of the present disclosure relate to a front-end module(FEM). The FEM may include a multiplexer network configured to receive asignal from a diversity antenna and to split the signal into a pluralityof signal portions corresponding to a plurality of communication bands.In addition, the FEM may include an integrous signal combiner configuredto receive the plurality of communication bands at a plurality ofinputs. Each, or at least some, of the inputs may receive a signalportion associated with a different communication band from theplurality of communication bands. Further, the integrous signal combinercan include the plurality of inputs and an output configured to providean integrous signal to a subsequent processing block. In addition, theintegrous signal combiner may include a plurality of low noiseamplifiers (LNAs) and a plurality of resonant circuits. Each, or atleast some, of the resonant circuits may correspond to a different LNAfrom the plurality of LNAs.

In certain embodiments, the FEM may further include a plurality offilters positioned between the multiplexer network and the integroussignal combiner. Each, or at least some, of the filters from theplurality of filters may receive a different signal portion from theplurality of signal portions and may be configured to remove out-of-bandsignals from the received signal portion. Moreover, the integrous signalcombiner, in some implementations, further includes a combinerconfigured to combine a plurality of integrous signals. Each, or atleast some, of the integrous signals from the plurality of integroussignals may be output by a different resonant circuit from the pluralityof resonant circuits. In some cases, the integrous signal is a multibandsignal created from a plurality of communication bands.

In some implementations, at least one resonant circuit from theplurality of resonant circuits includes a bypass switch that when closedcauses a filter circuit of the at least one resonant circuit to bebypassed. Moreover, the integrous signal combiner may further include aswitch between an LNA from the plurality of LNAs and a correspondingresonant circuit from the plurality of resonant circuits. The switch maybe configured to switch between a signal path that includes thecorresponding resonant circuit and a bypass path that does not includethe corresponding resonant circuit. In some cases, at least one resonantcircuit from the plurality of resonant circuits may include anadjustable capacitor enabling the at least one resonant circuit to bedynamically adjusted.

Some aspects of the present disclosure relate to a wireless device. Thewireless device may include an antenna configured to receive a carrieraggregated (CA) signal from a base station and a front-end module (FEM)including a multiplexer network and an integrous signal combiner. Themultiplexer network may be configured to split the CA signal received atthe antenna into a plurality of signal portions corresponding to aplurality of communication bands. The integrous signal combiner may beconfigured to receive the plurality of communication bands at aplurality of inputs. Each, or at least some, of the inputs may receive asignal portion associated with a different communication band from theplurality of communication bands. The integrous signal combiner caninclude the plurality of inputs, an output configured to provide anintegrous signal to a subsequent processing block, a plurality of lownoise amplifiers (LNAs), and a plurality of resonant circuits. Each, orat least some, of the resonant circuits may correspond to a differentLNA from the plurality of LNAs.

In some embodiments, the antenna is a diversity antenna and the FEM is adiversity FEM. Moreover, the FEM may further include a plurality offilters positioned between the multiplexer network and the integroussignal combiner. Each, or at least some, of the filters from theplurality of filters may receive a different signal portion from theplurality of signal portions and may be configured to remove noisecomponents from the received signal portion. In some cases, each, or atleast some, of the plurality of resonant circuits may be deactivatedwhen the FEM receives a single band signal from the antenna. At leastone resonant circuit from the plurality of resonant circuits may includean adjustable circuit element enabling the at least one resonant circuitto be dynamically tuned.

DETAILED DESCRIPTION

Introduction

One challenge with multiband carrier aggregation (“CA”), or signalprocessing, is the minimizing of noise from each signal path for eachcommunication band or bandwidth during the aggregation process.Typically, the signal path will include a low noise amplifier (LNA) toamplify a received signal. The use of an LNA is often necessary becausemany times the received signal will be too weak for use by the wirelessdevice when initially received by an antenna of the wireless device.However, in some cases, not only will the LNA amplify the desiredreceive signal, but it will also amplify some of the noise that is onthe receive line. This problem may be exacerbated in systems thatsupport carrier aggregation because such systems will include multiplelines configured to receive and process signals of different frequencybands. Thus, one CA signal comprising one set of frequency bands maycause and/or be affected by different noise frequency components on areceive line of the communication path of a wireless device compared toanother CA signal comprising a different set of frequency bands.

Another challenge with multiband carrier aggregation is the occurrenceof parasitic loading. With some implementations of multiband carrieraggregation, a separate communication path may exist for each processedcommunication band. Often, the multiple communication paths will beconfigured in parallel, which can result in a drop in impedance in eachcommunication path. Consequently, the drop in impedance along eachcommunication path can result in a drop in the gain and the power outputby the LNA in the communication path. One method of addressing thechallenge of minimizing noise and parasitic loading in the signal pathis to insert a pre-processing network prior to the LNA. Thispre-processing network may include phase shifters or switched combiners.However, the pre-processing of the signal can decrease signal integrityfor the received signal.

Embodiments described herein relate to a front-end module (FEM) that canprocess receive signals and that can include resonant circuits to filtersignal noise prior to recombination of a plurality of signal bands thatform the aggregate carrier signal. The resonant circuit is sometimesreferred to as a tuned circuit or a tank circuit. In someimplementations, the resonant circuit includes an inductor and capacitorcombination (e.g., an LC circuit). Alternatively, or in addition, theresonant circuit can include a crystal oscillator, a surface acousticwave (SAW) resonator, a bulk acoustic wave (BAW) resonator, or any othertype of resonance circuit that can be selectively configured based on areceived signal bandwidth. These resonant circuits may be placed afterthe LNA and can be used to more efficiently reduce noise and parasiticloading within each of the signal paths. In some cases, the resonantcircuits may reduce parasitic loading by maintaining the impedance ofthe signal path at a particular impedance (e.g., 50 Ω). In someembodiments described herein, the FEM may also include an impedancematching circuit to facilitate maintaining the particular impedanceand/or to match the impedance across each communication path and/or withan output path of the FEM, which may be to a transceiver or receiver.Each resonant circuit may be configured to filter noise relating to abandwidth for a signal that is to be combined with the signal of thesignal path that includes the resonant circuit. Thus, for example, aresonant circuit in a first signal path for processing a first signal ofa first frequency band may be configured to filter or reduce noise thatrelates to a second frequency band corresponding to a second signal ofthe second frequency band that is to be combined with the first signal.In certain embodiments, the resonant circuits may be reconfigurable ordynamically configurable.

Advantageously, in certain embodiments, the ability to reconfigure theresonant circuit enables the wireless device to process differentcombinations of frequency bands while reducing the size and complexityof the resonant circuits compared to solutions that include a separateresonant circuit for each supported communication band. Further, incertain embodiments, placing the resonant circuit subsequent to the LNAreduces or eliminates the reduction of signal integrity that can occurwith other carrier aggregation solutions and prevents additional signalloss.

Example Wireless Device

FIG. 1A is a block diagram of one example of a wireless device 100 thatincludes a primary front end module (FEM) 102 and a diversity FEM 134.The wireless device 100 may support multiple communications standards(such as 2G, 3G, 4G, and 4G LTE, and so forth). By way of example, thewireless device 100 can implement the Global System for Mobile (GSM)communication standard, which is a mode of digital cellularcommunication that is utilized in many parts of the world. GSM modecapable mobile phones can operate at one or more of four frequencybands: 850 MHz (approximately 824-849 MHz for Tx, 869-894 MHz for Rx),900 MHz (approximately 880-915 MHz for Tx, 925-960 MHz for Rx), 1800 MHz(approximately 1710-1785 MHz for Tx, 1805-1880 MHz for Rx), and 1900 MHz(approximately 1850-1910 MHz for Tx, 1930-1990 MHz for Rx). Variationsand/or regional/national implementations of the GSM bands are alsoutilized in different parts of the world.

Code division multiple access (CDMA) is another standard that can beimplemented in mobile phone devices. In certain implementations, CDMAdevices can operate in one or more of 800 MHz, 900 MHz, 1800 MHz and1900 MHz bands, while certain W-CDMA and Long Term Evolution (LTE)devices can operate over, for example, as many as twenty-two, or in somecases even more, radio frequency spectrum bands.

Further, the wireless device 100 can support multiband and/or multi-modecommunication. Moreover, it should be understood that the wirelessdevice 100 is but one non-limiting example of a wireless device and thatother embodiments of the wireless device 100 are possible.

In certain embodiments, in addition to the primary FEM 102 and thediversity FEM 134, the wireless device 100 can include a transceiver104, a baseband subsystem 106, a user interface processor 108, a memory110, a call processor 118, a central processor 120, a power managementcomponent 122, a digital signal processor (DSP) 124, one or more primaryantennas 132, one or more diversity antennas 136, and other components126. Some or all of these components may be electrically connected witheach other. Components that are electrically connected may be directlyconnected enabling a signal to be passed from one component to the nextcomponent. Alternatively, components that are electrically connected maybe indirectly connected such that one or more intermediary componentsmay exist between two components. A number of connections between thevarious components of the wireless device 100 are possible, and areomitted from FIG. 1A for clarity of illustration only and not to limitthe disclosure. For example, the power management component 122 may beelectrically connected to the baseband subsystem 106, the primary FEM102, the diversity FEM 134, the DSP 124, or other components 126. As asecond example, the baseband subsystem 106 may be connected to a userinterface processor 108 that may facilitate input and output of voiceand/or data provided to and/or received from the user.

Typically, the wireless device 100 can receive one or morecommunications signals via one or more primary antennas 132, one or morediversity antennas 136, or a combination of primary antennas 132 anddiversity antennas 136. In some cases, at least some of the receivedcommunication signals can be multiband signals. These multiband signalsmay include signals of multiple frequencies or of multiple frequencybands. In some cases, the frequency bands may be associated withstandardized communication frequencies. For example, band 1 of thelong-term evolution (LTE) standard may be centered around 2.1 GHz. Insome cases, a communication band may consist of a single frequency.However, in other cases, the communication band may have a largerbandwidth that includes a range of frequencies and is centered around acentral frequency. Thus, continuing the example of band 1 within the LTEstandard, the band for downlink may have a bandwidth of 60 MHz centeredaround 2140 MHz. In such a case, the band 1 may be between 2110 MHz and2170 MHz.

The transceiver 104 can generate RF signals for transmission via theprimary antenna(s) 132 and/or the diversity antenna(s) 134. Furthermore,the transceiver 104 can receive incoming RF signals from the primaryantenna(s) 132 and/or the diversity antenna(s) 136. As stated above, thereceived signals may be of different bands that can be aggregatedtogether by the diversity FEM 134, as will be described in more detailbelow. It will be understood that various functionalities associatedwith the transmitting and receiving of RF signals can be achieved by oneor more components that are collectively represented in FIG. 1A as thetransceiver 104. For example, a single component can be configured toprovide both transmitting and receiving functionalities. In anotherexample, transmitting and receiving functionalities can be provided byseparate components. The transceiver 104 may include a separate receiverand transmitter. In some implementations, the transceiver 104 isreplaced by a separate receiver component and a separate transmittercomponent. With wireless devices that are capable of processingmulti-band signals, the transceiver 104 may receive an aggregate signalfrom the diversity FEM 134.

In some cases, one or more of the antennas 132 and 136 of the wirelessdevice 100 may be configured to transmit and/or receive at differentfrequencies or within different frequency ranges. Further, one or moreof the antennas may be configured to work with different wirelessnetworks. Thus, for example, one primary antenna 132 may be configuredto transmit and receive signals over a 2G network, and another primaryantenna 132 may be configured to transmit and receive signals over a 3Gnetwork. In some cases, multiple antennas 132 may be configured totransmit and receive signals over, for example, a 2.5G network, but atdifferent frequencies. In some implementations, the diversity antennas136 may communication over the same networks as the primary antennas 132while in other implementations, the diversity antennas 136 may beconfigured to communication over different networks or differentfrequencies than the primary antennas 132.

In FIG. 1A, one or more communication signals may be communicatedbetween the transceiver 104 and the primary antennas 132 and/or thediversity FEM 134 via one or more transmission paths. Differentreceiving transmission paths can represent paths associated withdifferent bands. Moreover, although not illustrated, one or moretransmission paths may also exist between the transceiver 104 and thediversity FEM 134.

The diversity FEM 134 can be used to process signals received and/ortransmitted using the diversity antenna(s) 136. In certainconfigurations, the diversity FEM 134 can be used to provide filtering,amplification, switching, and/or other processing. Further, thediversity FEM 134 can be used to process a signal before providing thesignal to an antenna switch module (not shown), which can provide thesignal to the transceiver 104. In some cases, the diversity FEM 134 caninclude a number of switches for switching between high-band (HB),mid-band (MB), and/or low-band (LB) signals that may be received byand/or transmitted over one or more of the diversity antennas 136.

In some implementations, the wireless device 100 may further include anantenna switch module between the primary antennas 132 and the diversityantennas 136, and the primary FEM 102 and the diversity FEM 134. Theantenna switch module can determined based on a received signal and/or acontrol signal from, for example, the call processor 118 whether toprovide a received signal from a primary antenna 132 to a primary FEM102 or to provide a received signal from the diversity antenna 136 tothe diversity FEM 134. In certain embodiments, the wireless device 100may include a single FEM, and the antenna switch module can determinewhether to provide a received signal from the primary antenna 132 orfrom the diversity antenna 136 to the FEM.

The transceiver 104 may interact with a baseband subsystem 106 that isconfigured to provide a conversion between data and/or voice signalssuitable for processing by one or more user interface elements and RFsignals suitable for processing by the transceiver 104. The transceiver104 may also be electrically connected to a power management component122 that is configured to manage power for the operation of the wirelessdevice 100. Such power management can also control operations of thebaseband sub-system 106 and the FEMs 102 and 136, among othercomponents. Further, the power management component 122 may provide asupply voltage to a switch mode boost converter (not shown), which mayboost the voltage before providing the voltage to a power amplifier oran LNA. It should also be understood that the power management component122 may include a power supply, such as a battery. Alternatively, or inaddition, one or more batteries may be separate components within thewireless device 100.

The baseband sub-system 106 can also be connected to a memory 110 thatmay be configured to store data and/or instructions to facilitate theoperation of the wireless device 100, and/or to provide storage ofinformation for the user.

In some embodiments, the call processor 118 may be in communication withthe base station. The call processor 118 may be configured to controlone or more power amplifier modules (PAMs) or power amplifiers (PAs),which may be included as part of the FEM 102, the transceiver 104, orotherwise. Further, the call processor may configure the diversity FEM134 based on control information received from the base station and/orinformation included in a receive signal. For example, the callprocessor may configure the diversity FEM 134 based on a frequency bandof a receive signal. In some cases, multiple receive signals ofdifferent frequency bands may be received. In such cases, the callprocessor 118 may configure the diversity FEM 134 based on each of thedifferent frequency bands. More details on controlling the diversity FEM134 are disclosed below.

As previously mentioned, the wireless device 100 may include one or morecentral processors 120. Each central processor 120 may include one ormore processor cores. The central processor 120 typically facilitatesexecution of processes on the wireless device, such as applications. Thecentral processor 120 may interact with the user interface processor 108to interact with a user. The user interface processor 108 may includeany system for interacting with a user of the wireless device 100. Theuser interface processor may consist of multiple systems. For example,the user interface processor 108 may include a graphics processor, anI/O processor, an audio processor, and so forth. In some cases, thecentral processor 120 may facilitate wireless functionality of thewireless device 100. However, in other embodiments, wirelesscommunication or cellular communication management is handled by thecall processor 118 and the central processor 120 may or may not beinvolved in wireless communications.

A number of other wireless device configurations can utilize one or morefeatures described herein. For example, a wireless device can includeadditional antennas and additional connectivity features such as Wi-Fi,Bluetooth, and GPS. Further, the wireless device 100 may include anynumber of additional components 126, such as analog to digitalconverters, digital to analog converters, graphics processing units,solid state drives, etc. Moreover, the wireless device 100 can includeany type of device that may communicate over one or more wirelessnetworks and that may include a diversity FEM 134. For example, thewireless device 100 may be a cellular phone, including a smartphone or adumbphone, a tablet, a laptop, a video game device, a smart appliance,etc.

FIG. 1B is a block diagram of one example of the wireless device 100 ofFIG. 1A in communication with a base station 150. Although the element150 is described as a base station, the present disclosure is notlimited as such and the wireless device 100 may be in wirelesscommunication with any device that is capable of wirelesslycommunicating with the wireless device 100.

The base station 150 may communicate with the wireless device 100 usingone or more communication bands or frequencies. For example, the basestation 150 may communicate using a single band signal 152 tocommunicate with the wireless device 100. Alternatively, or in addition,the base station 150 may communicate using multiple communication bandsvia, for example, a carrier aggregation signal 154 that aggregatesmultiple communication bands together as part of a single communicationsignal. As illustrated by the thicker lightning bolt representative ofthe signal 154 compared to the thinner lightning bolt representative ofthe signal 152, the signal 154 may be comprised of multiplecommunication bands while the signal 152 may comprise a singlecommunication band.

In some embodiments, a negotiation process between the base station 150and the wireless device 100 may occur to determine which communicationbands to use for communication between the wireless device 100 and thebase station 150, and/or whether to use single band and/or CAcommunication. This negotiation may be based on the supportedcapabilities of the wireless device 100 and/or the base station 150, theutilization rate of the base station 150, whether the communication isfor voice, data, or both, and any other factor that may impact theselected communication band(s) between the wireless device 100 and thebase station 150. In certain embodiments, once it has been establishedwhether CA will be used and the particular communication bands that willbe used for communication between the wireless device 100 and the basestation 150, the base station 150 may provide a command to the wirelessdevice 100 identifying the communication band(s) to be used forcommunication. These command may then be used by, for example, the callprocessor 118 to configure various elements of the wireless device 100including, for example, the diversity front end module 134. Some of thepossible configuration options are described in more detail below withrespect to the additional discussion of the diversity front-end modules.

Example Front-End Module

FIG. 2A is a block diagram of one example of the diversity front endmodule 134 that can be included in the wireless device 100 of FIG. 1A.The diversity FEM 134 may receive one or more signals directly orindirectly from one or more antennas. For instance, the FEM 134 mayreceive a CA signal from a diversity antenna 136. In someimplementations, a single signal of multiple frequency bands may bereceived by the diversity FEM 134. This signal may then be split intomultiple signals of different frequency bands. Each of the multiplesignals may then undergo additional processing. For example, theindividual signals may be amplified by an LNA. After the multiplesignals are processed, they may be recombined to form an aggregatesignal across a wider bandwidth than each of the individual signals. Thecombined signal may be provided to another system, such as thetransceiver 104, for further processing.

In some instances, the diversity FEM 134 may receive a single signal ofa single communication or frequency band. In some such cases, some orall of the components of the diversity FEM 134 may operate in a bypassmode. Certain non-limiting embodiments of the bypass mode are describedin further detail below with respect to FIG. 2B. In other cases, thesignal may be amplified and/or undergo other signal conditioning andprocessing, but components relating to the splitting and recombining ofthe signal may operate in a bypass mode.

The diversity FEM 134 includes a diplexer or multiplexor network 202,which may receive a signal from an antenna, such as a signal from thediversity antenna 136. The signal may be a multiband signal or a singleband signal. In the case that the signal is a single band signal, themultiplexor network 202 may provide the signal to a filter correspondingto the frequency band of the signal. For example, supposing that thesignal is of a frequency associated with band 2 (e.g., approximately1.96 GHz as in the case of 4G LTE) and that the filter 204 b is a bandpass filter configured to pass frequencies associated with band 2 and toblock other frequencies, the multiplexor 202 may provide the signal tofilter 204 b. The filter 204 b may filter out any noise or out-of-bandsignals included with the received signal. Further, the multiplexor 202may function in a bypass or pass-through mode when the receive signal isa single band signal.

In the case where the received signal is a multiband signal, or a signalassociated with multiple communication bands, the multiplexer 202 maydivide the signal into its constituent bands. It should be understoodthat various multiband signals may comprise different bands and thus,not all of the illustrated signal paths of the diversity FEM 134 may beutilized for a particular signal. The multiplexor 202 can provide eachsignal corresponding to a particular communication band or frequency toa corresponding filter 204 a, 204 b, 204 n. In some implementations, themultiplexor 202 divides the received multiband signal into multiplebands because the filters 204 a-204 n may not be capable of processingthe entire bandwidth of the multiband signal. In other cases, thefilters 204 a-204 n can be designed more efficiently across a narrowerbandwidth than the bandwidth of the multiband signal

As previously stated, the filters 204 a, 204 b, 204 n may filter out anyout-of-band signals included in the constituent signals of the multibandsignal. Further, the filters may filter any noise, transmit signalinterference, or other interference which is outside of the signal band.The filters 204 a-204 n can use any type of filter for filtering thenoise or interference from a signal. For example, the filter may be asurface acoustic wave (SAW) filter or a bulk acoustic wave (BAW) filter.In one example use case, the multiband signal may include two signalbands. The multiplexor 202 may divide the signal into its constituentsignal bands to obtain a first signal and a second signal. Themultiplexor 202 may then provide the first signal to the filter 204 aand the second signal to the filter 204 b, or vice versa. The diversityFEM 134 can be configured to support any number of signal bands. Thus,the diversity FEM 134 can include any number of filters to process eachof the signal bands. In some embodiments, the filters 204 a-204 n may beoptional or omitted.

The diversity FEM 134 may further include a tunable integrous signalcombiner 210. The tunable integrous signal combiner 210 is a signalcombiner that can maintain the integrity of a set of one or more signalsthat are being processed. This processing may include signalamplification and noise removal, among other processing operations.Further, in the case where a plurality of signals are processed, thesignal integrity may be maintained for the plurality of signals as theyare combined after processing by the tunable integrous signal combiner210. This, in certain embodiments, a plurality of signal or signalcomponents may be amplified along one or more communication paths andthen combined into a single multiband signal without reduced signalintegrity due to noise or undesired signals or signal harmonics.

The tunable integrous signal combiner 210 amplifies the individualsignal or frequency bands included in a CA signal while filtering outundesirable signals, such as noise for each of the individual signalbands. It should be understood that, in some instances, signals of aparticular frequency may be considered noise for one signal path whilebeing a desired frequency for another signal path. Further, in certainembodiments, the integrous signal combiner 210 can be tuned to processsignals of different frequencies. Thus, the tunable integrous signalcombiner 210 can be configured to process different CA signals that maybe received from, for example, a base station. Although described astunable, in certain implementations, the integrous signal combiner 210may be application-specific and may not be tunable. However, in otherimplementations, the integrous signal combiner 210 is a tunableintegrous signal combiner 210 that can be tuned to process differentsignal bands and different CA signals and/or bands.

The tunable integrous signal combiner 210 may include one or more lownoise amplifiers (LNAs) 206 a, 206 b, 206 n. Although only three LNAsare illustrated, it should be understood that the integrous signalcombiner 210 may include any number of LNAs. For example, the integroussignal combiner 210 may include an LNA for each frequency band supportedby the wireless device 100. Each LNA may receive and/or process (e.g.,amplify) a signal associated with a particular frequency band. Forexample, the LNA 206 a may receive a signal of a first band and the LNA206 b may receive a single of a second band. These signals may bereceived from the filters 204 a-204 n. For example the LNA 206 a mayreceive a filtered signal from filter 204 a and the LNA 206 b mayreceive a filtered signal from filter 204 b. Each of the LNAs 206 a-206n can amplify the portion of the received signal provided by thecorresponding filter 204 a-204 n. The LNAs may amplify signals that maybe too weak for processing by the transceiver 104 to boost the signalsuch that the transceiver 104 can process the signal. In certainembodiments, particular LNAs associated with frequency bands of themultiband signal may be active, while other LNAs included in thediversity FEM 134 that are configured to amplify frequency bands notincluded in the multiband signal may be inactive or unused.

When amplifying a signal, the LNA may act as a broadband device. Thus,not only is the desired frequency band amplified, but so is any residualnoise or interference from other bands. In certain embodiments, thenoise or spurious signals may not impact the operation of thetransceiver 104 that receives the output from the diversity FEM 134. Forexample, when the signal received from the antenna is of a singlefrequency or frequency band, the output of the LNA may be provided tothe transceiver 104 without further processing.

However, in other embodiments, the noise or undesired amplifiedfrequencies can impact operation of the transceiver 104. For example, incases where the received signal is a multiband signal, the amplifiednoise from each LNA output may join together through, for example,superposition. In other words, each noise component for a particularfrequency may add together causing noise at the particular frequency toreach an intensity level that can cause degradation in the performanceof the transceiver 104.

To prevent this additive noise from interfering with operation of thetransceiver 104, or other signal processing components of the wirelessdevice 100, the tunable integrous signal combiner 210 includes a numberof resonant filters or circuits 208 a, 208 b, 208 n. Each of theresonant filters 208 a-208 n may be configurable LC filters. Forexample, the resonant filters 208 a-208 n may each include a network ofswitchable capacitors that may be controlled by, for example, the callprocessor 118 and/or based on the received signal(s). Moreover, theswitchable capacitors may be configured based at least in part on acontrol signal received from an external source, such as a base station.In some cases, as illustrated in FIG. 2A, the resonant filters 208 a-208n may be tank circuits. However, as previously described, it should beunderstood that the resonant circuits are not limited as such and caninclude other types of resonant circuits.

Each of the resonant filters 208 a-208 n can be configured to filter outsignals associated with one or more frequency bands not being amplifiedor processed by the corresponding LNA 206 a-206 n in electricalcommunication with the resonant filters 208 a-208 n. Thus, for example,the resonant filter 208 a, which is in electrical communication with theLNA 206 a, may be configured to filter out frequencies that are notassociated with the frequency band associated with or amplified by theLNA 206 a. Therefore, each of the resonant filters 208 a-208 n canoutput an integrous signal that comprises an amplified version of thesignal received by the corresponding LNA 206 a-206 n without or with areduced noise signal. Thus, the output of the integrous signal combiner210 is a more pure version of a signal received by the intergrous signalcombiner 210 compared to signal combiners that do not include resonantcircuits.

In some cases, the resonant filters 208 a-208 n serve as notch orbandpass filters that permit the frequency band associated with thecorresponding LNA 206 a-206 n while filtering out all other frequencies.However, in certain implementations, the resonant filters 208 a-208 bare configured to filter out noise associated with the selected bandsamplified by the active LNAs not in electrical communication with theparticular resonant filters.

For instance, suppose that a multiband signal is received by thediversity FEM 134 that includes bands 1 and 3. The multiplexor 202 maysplit the signal into two components or signals, one signalcorresponding to the band 1 frequency and one signal corresponding tothe band 3 frequency. The band 1 signal may be provided to the LNA 206a, which can amplify the band 1 signal, and the band 3 signal may beprovided to the LNA 206 b, which can amplify the band 3 signal. In thisparticular example, the resonant circuit 208 a may be configured tofilter any noise associated with the band 3 signal. Similarly, theresonant circuit 208 b may be configured to filter any noise associatedwith the band 1 signal.

The filtered and amplified signals output by the resonant circuits 208a-208 n are combined at the node 212 to form an aggregate signal. Thisaggregate signal may be output to the transceiver 104. As previouslydescribed, some of the communication paths, and corresponding LNAs, inthe diversity FEM 134 may be inactive. For instance, if the receivedmultiband signal includes less frequency bands than supported by thewireless device 100, less than all of the LNAs may be active. In suchcases, the aggregate signal at the node 212 may be formed from less thanall of the LNA and resonant filter combinations. In some cases, such aswhen a non-CA signal is received by the wireless device 100 at thediversity antenna 136, the amplified signal output by the LNA thatcorresponds to the frequency of the signal may be provided to the node212 for output from the tunable integrous signal combiner 210. Thus, insuch cases, the signal is not an aggregate signal because, for example,there is only a single processed signal or frequency band.

As illustrated in FIG. 2A, the tunable integrous signal combiner 210 maybe implemented as a single device that includes the LNAs 206 a-206 n andthe resonant filters 208 a-208 n. However, in other implementations, thetunable integrous signal combiner 210 may be implemented as part of amultichip module (MCM). For example, the LNAs 206 a-206 n may beimplemented in one chip or die and the resonant circuits 208 a-208 n maybe implemented on another chip or die. As a second example, each LNA andcorresponding resonant circuit pair may be implemented as a separatechip (e.g., amplification block 250), which can then be combined as aMCM to create the tunable integrous signal combiner 210.

In some embodiments, the diversity FEM 134 may be created on a singlechip that includes the tunable integrous signal combiner 210 or as itsown MCM that may include the tunable integrous signal combiner 210 as asingle die or an MCM as well as a number of separate dies thatcorrespond to the rest of the FEM's 134 components. In someimplementations, the tunable integrous signal combiner 210, orcomponents thereof, may be formed of a different material than othercomponents of the tunable integrous signal combiner 210 or the diversityFEM 134. For example, the multiplexor 202 may be formed in silicon whilethe tunable integrous signal combiner 210 210 may be formed in SiliconGermanium (SiGe).

As previously described, combining the multiple signals prior to theprocessing by the LNAs may result in a degradation of the signal and thesignal to noise ratio (SNR) of the received signal. By amplifying thesignal with the LNAs 206 a-206 n and post filtering with the resonantcircuits 208 a-208 n, the degradation of the signal is reduced orprevented.

Often, the primary antennas 132 and the primary FEM 102 are locatedrelatively close to the transceiver 104. For instance, the primary FEM102 may be located next to the transceiver 104. As such, the signalpaths between the primary FEM 102 and the transceiver 104 may berelatively short. For this reason, it may be unnecessary for the primaryFEM 102 to include the resonant circuits described above with respect tothe diversity FEM 134 and the resonant circuits may be omitted to reducecost and packaging size of the FEM 102. However, in some embodiments,the wireless device may include the transceiver 104 closer to thediversity front end module 134. In such cases, the primary FEM 102 mayinclude the resonant circuits and the diversity FEM 134 may omit theresonant circuits 208 a-208 n. In yet other implementations, both theprimary FEM 102 and the diversity FEM 134 may be designed with theresonant circuits.

Example Bypass Mode

In certain embodiments, portions of the tunable integrous signalcombiner 210 may operate in a bypass mode. For example, in cases where areceived signal corresponds to a single communication band because, forexample the signal from the base station 150 is not a CA signal. Asanother example, portions of the tunable integrous signal combiner 210may operate in a bypass mode because the CA signal comprisescommunication bands processed by communication paths of the tunableintegrous signal combiner 210 that are unlikely to introduce noise orcause parasitic loading with other communication paths of the tunableintegrous signal combiner 210.

FIG. 2B is a block diagram of a portion, the amplification block 250, ofthe front-end module 134 of FIG. 2A that illustrates several embodimentsfor implementing a bypass mode in response to a command from, forexample, the call processor 118. This portion of the front-end module134 may be one of the plurality of communication paths included in thetunable integrous signal combiner 210 and may be associated with aparticular communication band or frequency.

Amplification block 250 includes an LNA 206 a and a resonant circuit 208a. As previously described, the resonant circuit 208 a may be an LCfilter that includes an inductor 252 and a switch capacitor 254.Further, the resonant circuit may include a switch 256 that may beclosed in response to a command from, for example, the call processor118. This command may be responsive to a command from the base station150 identifying the communication band(s) to be used for communicatingbetween the wireless device 100 and the base station 150. Moreover, theswitch 150 may be closed when the communication signal (e.g., the signal154) does not include a frequency band associated with the LNA 206 aand/or when the received signal is not a CA signal, but a single bandsignal (e.g., the signal 152).

As an alternative, or in addition, to the switch 256 included by theresonant circuit 208 a, the amplification block 250 may include one ormore switches before and/or after the resonant circuit 208 a. Forexample, the switch 260 between the LNA 206 a and the resonant circuit208 a can control whether a signal is provided from the LNA 206 a to theresonant circuit 208 a or to a bypass path 264 that bypasses theresonant circuit 208 a. As another example, the switch 262 between theresonant circuit 208 a and the path to the combiner (e.g., the node 212of FIG. 2A) can control whether a signal is provided to the combinerfrom the resonant circuit 208 a or the bypass path 264. Advantageously,in certain embodiments, bypassing the resonant circuit 208 a can resultin lower insertion loss. Thus, when operating in a single band mode orwhen receiving a CA signal with certain frequency bands, it can beadvantageous to bypass the resonant circuit 208 a. In other embodiments,the use of the resonant circuit 208 a can result in reduced oreliminated noise and parasitic loading. Moreover, in certainembodiments, when receiving a single band signal, a combiner at theoutput of the tunable integrous single combiner 210 (e.g., at node 212)that combines the outputs of each of the amplification blocks may bebypassed resulting in lower insertion loss.

In certain implementations, each of the amplification blocks comprisingthe LNAs and the resonant circuits can include one or more of theswitches 256, 260, and 262. Further, each of the communication paths ofthe tunable integrous signal combiner 210 may include an amplificationblock that is configured the same as the amplification block 250.Alternatively, at least some of the amplification blocks may beconfigured differently.

Second Example Front-End Module

FIG. 3 is a block diagram of another example of a front end module 300that can be included in the wireless device 100 of FIG. 1A. The FEM 300can include a number of the components of the diversity FEM 134previously described with respect to FIG. 2A. Thus, reference numbersfrom FIG. 2A are re-used in FIG. 3 to indicate correspondence betweenreferenced elements.

In addition to the elements previously described with respect to FIG.2A, the FEM 300 may include an impedance matching network 302. Thisimpedance matching network 302 may be used to facilitate combining thesignals output by the one or more resonant circuits 208 a-208 n.Further, the impedance matching network 302 may be configured to matchan impedance of the output of the tunable integrous signal combiner 310to the impedance of an element in electrical communication with the FEM300, such as the transceiver 104. As illustrated, the impedance matchingnetwork 302 may be part of tunable integrous signal combiner 310.Further, the impedance matching network 302 may be implemented on thesame component, die, or as part of the same circuitry as the tunableintegrous signal combiner 310 or, in implementations where the tunableintegrous signal combiner 310 is part of a MCM, the impedance matchingnetwork 302 may be implemented as part of a separate module that isseparate from at least some other components of the tunable integroussignal combiner 310.

As yet another alternative, the impedance matching network 302 may beimplemented on a separate component from the tunable integrous signalcombiner 310. Thus, in some such cases, an output of the tunableintegrous signal combiner 310 may be provided as an input to theimpedance matching network 302, which may in turn output a signal fromthe FEM 300 to a subsequent system, such as a transceiver 104. In someimplementations where the impedance matching network 302 is external tothe tunable integrous signal combiner 310, the signals processed by theLNA and/or resonator circuits of the tunable integrous signal combiner310 may be aggregated before being output by the tunable integroussignal combiner 310 and provided to the impedance matching network 302.In other implementations, the tunable integrous signal combiner 310 mayhave multiple outputs with each output corresponding to LNA/resonantcircuit signal path. Each of the outputs may then be provided to theimpedance matching network 302, which may perform the aggregation of thesignals output by the tunable integrous signal combiner 310 beforeproviding the aggregated signal as an output of the FEM 300.

As previously described, the combination of communication paths used toperform carrier aggregation can result in parasitic loading. In someimplementations, the resonant circuits 208 a-208 n may be used to reduceor eliminate parasitic loading by, for example, adjusting the impedanceon the output line of the respective LNAs 206 a-206. Alternatively, orin addition, the parasitic loading can be reduced or eliminated by usingthe impedance matching network 302. The impedance matching network 302can be configured to raise, or otherwise modify, the impedance of theoutput line of the LNAs to counter any reduction in impedance due to theparallel configuration of the communication paths within the tunableintegrous signal combiner 310. Further, the impedance matching network302 can be used to match the impedance of the aggregate communicationpath between the diversity FEM 300 and a subsequent system, such as thetransceiver 104.

In some cases, the impedance matching network 302 can be bypassed. Forexample, in cases where a single band signal is received, it may beunnecessary to adjust the impedance of the communication path because,for example, all but one communication path may also be configured in abypass mode.

In certain embodiments, the impedance matching network 302 may be adynamic impedance matching network. Advantageously, in certainembodiments, using a dynamic impedance matching network 302 enables theimpedance to be adjusted or matched based on the one or more LNA and/orresonant circuits that are active. One example of a tunable impedancematching network that can be adapted for use with certain embodimentsdescribed herein is described in U.S. application Ser. No. 14/314,550,filed on Jun. 25, 2014 and titled “FLEXIBLE L-NETWORK ANTENNA TUNERCIRCUIT,” which is hereby incorporated herein by reference in itsentirety for all purposes. Another example of an impedance matchingnetwork that can be adapted for use with certain embodiments describedherein is described in U.S. application Ser. No. 14/869,041, filed onSep. 29, 2015 and titled “AUTOMATIC IMPEDANCE MATCHING USING TRUE POWERINFORMATION,” which is hereby incorporated herein by reference in itsentirety for all purposes.

In addition to matching the impedance of the output lines of the activeLNAs 206 a-206 n and/or the active resonant circuits 208 a-208 n, theimpedance matching network 302 may combine the signals output by theactive LNAs 206 a-206 n and/or the active resonant circuits 208 a-208 nto create the aggregate carrier signal. The impedance matching network302 can provide this aggregate carrier signal to the transceiver 104.Further, the impedance matching network 302 may match the impedance ofthe tunable integrous signal combiner 310 to the transceiver 104.

Example Resonant Circuit Schematics

FIGS. 4A-4D are circuit schematics of examples of resonant circuits 400,410, 420, and 430 that can be included in the front end modules of FIGS.2A and 3. In some embodiments, each of the resonant circuits 400, 410,420, and 430 are separate resonant circuits that can be electricallyconnected to one or more of the LNAs of FIGS. 2A and 3. The resonantcircuits 400, 410, 420, and 430, in some cases, may each be staticallyconnected to different LNAs. Alternatively, a switching network may beused to connect one or more of the resonant circuits 400, 410, 420, and430 to a particular LNA. A control circuit included with the FEM 134 maydetermine which LNA to electrically connect to a particular resonantcircuit (or vice versa) based on the bandwidth of a received signal.Alternatively, the call processor 118 may make this determination.

In some embodiments, the resonant circuits 400, 410, 420, and 430 mayeach represent different configurations of a single resonant circuit. Inother words, the capacitor of the resonant circuits 400, 410, 420, and430 may be a set of switchable capacitors that can be electricallyconnected or disconnected from the resonant circuit based on thereceived signal, a command received from an external device (e.g., abase station), or the frequency band(s) processed by a particular one ormore LNAs.

The frequency bands filtered by each of the resonant circuits 400, 410,420, and 430 are summarized in the below Table 1, which also includes anoperating frequency for the associated communication band.

TABLE 1 FIG. 4A FIG. 4B FIG. 4C FIG. 4D B1/4 B3 B2 B30 C(pF) 9.25 12.411 7.62 L(nH) 0.6 0.6 0.6 0.6 Freq. (GHz) 2.14 1.85 1.96 2.35

The resonant circuit 400 of FIG. 4A is configured to filter frequenciesassociated with bands 1 and 4. The capacitor of resonant circuit 400 isconfigured to be 9.25 pF with an inductor of 0.6 nH. As indicated inTable 1, the resonant circuit 400 can be utilized with multiple bands.This is possible because the frequency band of band 1 and 4 are verysimilar. The middle downlink frequency of band 1 is 2.140 GHz and themiddle downlink frequency of band 4 is 2.1325 GHz. Advantageously, incertain embodiments, the resonant circuit 400 may be used in cases whereband 1, band 4, or band 1 and band 4 are included as part of thereceived multiband signal.

The resonant circuit 410 of FIG. 4B is configured to filter frequenciesassociated with band 3. The capacitor of resonant circuit 410 isconfigured to be 12.4 pF with an inductor of 0.6 nH. Further, theresonant circuit 420 of FIG. 4C is configured to filter frequenciesassociated with band 2. The capacitor of resonant circuit 420 isconfigured to be 11 pF with an inductor of 0.6 nH. Moreover, theresonant circuit 430 of FIG. 4D is configured to filter frequenciesassociated with band 30. The capacitor of resonant circuit 430 isconfigured to be 7.62 pF with an inductor of 0.6 nH.

As described, the inductors of each of the resonant circuits may beconfigured with the same inductance, and the capacitors may be varied tofilter or process different communication bands. However, in someembodiments, the capacitors may be of the same value and the inductorsmay be varied. In yet other implementations, both the capacitors andinductors may be varied. Thus, in some embodiments, one or more of theresonant circuits 400, 410, 420, or 430 may be tunable. Thus, one ormore of the capacitors and/or inductors of one or more of the resonantcircuits may be adjustable based, for example, on a received signal, acommand from a component internal to the wireless device 100 (e.g., thecall processor 118), and/or a command from an external component (e.g.,a base station). In order for the resonant circuits to be tunable, thecapacitors and/or inductors of the resonant circuits may bereconfigurable. For example, the capacitors may be switch capacitorsthat can be modified by, for example, opening or closing particularswitches of the switch capacitor.

In certain embodiments, two or more resonant circuits can be tiered orconnected in series enabling the rejection of multiple bands ondiffering frequency bands. Thus, for example, a LNA configured toamplify band 2 can be connected with a resonant circuit 400 and aresonant circuit 410 to reject signals of bands 1, 3, and 4. The outputsignal can in turn be combined with the output signals of LNAsconfigured to amplify bands 1, 3, and 4, which are connected in seriesto the resonant circuit 420, which rejects signals of band 2.

Resonant Circuit Simulations

FIGS. 5A-5D graphically illustrate simulations demonstrating a result ofapplying the resonant circuits 400, 410, 420, and 430 to a signal outputby an LNA to filter noise for different bands of operation. FIG. 5A is asimulation of the resonant circuit 400 as applied to an LNA configuredto process a band 2 or band 3 signal frequency. In other words, FIG. 5Aillustrates the result of processing a signal by an LNA designed toamplify band 2 and band 3 signals electrically connected in series withthe resonant circuit 400 configured to filter out signals associatedwith bands 1 and 4. Point m1 in the graph of FIG. 5A represents thecentral downlink frequency for band 1 and points m2 and m5 represent thelow and high frequency points. As illustrated by the graph at point m1,the rejection at the center frequency of band 1 is about −9.749 dB.Further, the rejection at the high frequency point of band 1 is −7.950dB compared to a loss at the high frequency components of bands 2 and 3,which is 0.834 and 2.104 dB, respectively.

As indicated by the points m3 and m4, the resonant circuit 400 can havesome impact on the desired signal to be passed to the transceiver 104.However, the impact is relatively small and the band 2 and band 3signals remain strong enough for processing by the transceiver 104. Insome cases, the LNA can be configured to provide a greater amplificationfactor to the received band 2/3 signal to account for the loss due tothe resonant circuit. In some implementations, the resonant circuit isconfigured to operate in a bypass mode when a single band signal isreceived. Advantageously, by configuring the resonant circuit to operatein a bypass mode when the signal is a single band signal, loss due tothe resonant circuit is eliminated. Similarly, the resonant circuit mayoperate in a bypass mode when a multiband signal is composed offrequencies that are more than a threshold apart from each other.

FIG. 5B is a simulation of the resonant circuit 410 as applied to an LNAconfigured to process a band 1 signal frequency. As can be seen bypoints m7 and m10, the frequencies associated with band 3 are rejectedwhile the signals associated with band 1 are primarily passed through asindicated by points m8 and m9, which represent the low and highfrequency points of band 1 respectively. Thus, looking at FIGS. 5A and5B in conjunction, a multiband signal composed of a band 1 signal and aband 3 signal can be divided into two separate signals by multiplexor202. The band 1 signal may be provided to an LNA configured to amplifythe band 1 signal, which may be connected in series to the resonantcircuit 410, which will filter any noise relating to band 3. Similarly,the band 3 signal may be provided to an LNA configured to amplify theband 3 signal, which may be connected in series to the resonant circuit400, which will filter any noise relating to band 1. The two signals maythen be recombined before being provided to the transceiver 104 forfurther processing.

FIG. 5C is a simulation of the resonant circuit 430 as applied to an LNAconfigured to process a band 4 signal frequency. The point m17represents the middle frequency for band 30, which indicates a rejectionof about 10.5 dB. Conversely, the point m15 associated with the band 4high frequency indicates a loss of only about 1.5 dB.

FIG. 5D is a simulation of the resonant circuit 420 as applied to an LNAconfigured to process a band 1 signal frequency. The points m11 and m14represents the low and high frequency respectively for band 2, whichindicates a rejection of over 7 dB. Conversely, the points m12 and m13associated with the band 1 low and high frequency respectively indicatea loss of 1.6 dB or less.

Example Fem Circuit Schematic

FIG. 6 is a circuit schematic 600 of one example of the front end module102 that can be included in the wireless device 100 of FIG. 1A. Thecircuit schematic 600 includes a filter 602, such as a triplexer thatcan be used to divide a multiband signal into its constituent frequencybands. In this particular example, the filter 602 splits a multibandsignal composed of a band 1 signal, a band 3 signal, and a band 7signal. The filter 602 may include any type of filter. For example, thefilter 602 may be a SAW filter or a BAW filter.

In certain embodiments, one band may be treated distinctly from theother bands because, for example, the frequency is different enough thatthere is minimal interference between the band and the other bands ofthe multiband signal. For example, the band 7 may be processedseparately from bands 1 and 3 because band 7 is relatively distant fromband 1 (approximately 450 MHz), and even more so from band 3(approximately 740 MHz), compared to the distance between bands 1 and 3.Thus, the amount of interference between bands 1 and 3, and band 7 issufficiently low enough to omit a resonant circuit, which can add itsown loss. As such, band 7 is processed separately by a circuit 604. Thedetails of this circuit 604 are omitted as beyond the scope of thepresent disclosure and thus circuit 604 is represented as a 50 Ωimpedance. It should be appreciated that in some embodiments, band 7could be processed similarly to bands 1 and 3 using an LNA and resonantcircuit combination.

The circuit schematic 600 may further includes an LNA 606 for processingor amplifying the band 1 signal and an LNA 608 for processing oramplifying the band 3 signal. Each of the LNAs 606 and 608 can berepresented by a scattering parameter (S2P) model.

The outputs of the LNAs 606 and 608 are provided to the resonantcircuits 410 and 400, respectively. As previously described, theresonant circuit 410 can filter or reject frequencies relating to theband 3 communication band. Similarly, the resonant circuit 400 canfilter or reject frequencies relating to the band 1 communication band.The amplified and filtered communication bands are recombined at node610, which may be output to a subsequent element, such as thetransceiver 104. This subsequent device element is represented by theresistor subsequent to the node 610, which can further be represented bya particular impedance, such as a 50 Ω impedance.

Simulations of an FEM

FIGS. 7A and 7B graphically illustrate simulations for the circuitschematic 600 of FIG. 6. More specifically, FIGS. 7A and 7B illustratecomparisons for two different bands between a single band operation, amultiband operation without using resonant circuits, and a multibandoperation with the use of resonant circuits.

FIG. 7A illustrates the results for processing a band 3 signal. In eachof the graphs, the solid line represents single band processing for band3. In other words, the solid line represents the case where a singleband signal is received by an antenna of the wireless device and nocarrier aggregation is performed. Further, in each of the graphs, thesolid line with the dots represents when carrier aggregation isperformed that includes band 3, but does not use a resonant circuit. Thedashed line represents when carrier aggregation is performed thatincludes a band 3 signal and uses a resonant circuit.

Examining the gain in graph 706, we see that the gain using the resonantcircuit is better than when carrier aggregation is used without the useof a resonant circuit. However, the resonant circuit does introduce someloss. Thus, in certain embodiments, when a non-multiband signal isreceived, the resonant circuit can be bypassed or operated in a bypassmode resulting in improved gain.

Further, examining the noise figure graph 708, we can see that carrieraggregation without the use of resonant circuits results in greaternoise. However, when resonant circuits are used, the noise level of theaggregate carrier signal approaches that of a single band signal.

FIG. 7B illustrates the results for processing a band 1 signal. As withFIG. 7A, in each of the graphs, the solid line represents single bandprocessing for band 1. In other words, the solid line represents thecase where a single band signal is received by an antenna of thewireless device and carrier aggregation is not performed. Further, ineach of the graphs, the solid line with the dots represents when carrieraggregation is performed that includes band 1, but does not use aresonant circuit. The line dashed line represents when carrieraggregation is performed that includes a band 1 signal and uses aresonant circuit.

Moreover, as with the graph 706, the graph 714 illustrates less of again loss when using a resonant circuit compared to not using a resonantcircuit for a multiband signal. Further, turning to graph 716, the noisefigure when using the resonant circuit is close to the single band caseand is much improved compared to carrier aggregation without a resonantcircuit.

Example Multiband Signal Processing Process

FIG. 8 is a flowchart of one example of a multiband signal processingprocess 800 for performing signal aggregation. It should be understoodthat the process 800 is one example of a process for performing carrieraggregation in response to receiving a multiband signal. Other processesfor processing a multiband signal are possible. For example, operationsof the process 800 may be performed in a different order orsubstantially in parallel. Thus, the order of the operations describedwith respect to the process 800 is for ease of description and not tolimit the process 800. Moreover, it should be understood that a varietyof systems, including a variety of hardware, software, firmware, or acombination thereof can implement at least portions of the process 800.For example, the process 800 may be performed, at least in part, by thecall processor 118, the diversity FEM 134, or the transceiver 104, orcombinations of the same, and so forth. To simplify discussion and notto limit the present disclosure, the process 800 will be described withrespect to particular systems.

The process 800 may begin when, for example, the wireless device 100receives a multiband signal including at least a first signal of a firstbandwidth and a second signal of a second bandwidth at block 802.Although the multiband signal is described as being a dual band signal,it is possible for the multiband signal to be tri-band or to include anyother number of frequency bands. Further, the received multiband signalmay be received at one or more primary antennas 132 and/or diversityantennas 136 of the wireless device 100. The multiband signal may bereceived from a base station or other system that can wirelesslycommunicate with the wireless device 100.

At block 804, a controller, such as the call processor 118, determines abandwidth or a frequency band of the first signal of the multibandsignal. In some cases, the communication band is determined based on thereceived signal. In other cases, the communication band may bedetermined based on a previous received signal or data packet. In somecases, the base station informs the wireless device of the communicationbands to be received. At block 806, the communication band for thesecond signal is determined.

At block 808, a first resonant circuit associated with a first LNA isconfigured to filter noise associated with the second bandwidth orcommunication band determined at the block 806. Similarly, at block 810,a second resonant circuit associated with a second LNA is configured tofilter noise associated with the first bandwidth or communication banddetermined at the block 804. The resonant circuits may be dynamicallyconfigured by electrically connecting or disconnecting one or moreswitched capacitors from the respective LNAs. In some cases, theresonant circuit configurations are static, but the resonant circuitsthat are in electrical communication with the LNA can be adjusted. Inother words, although the resonant circuit's configuration may bestatic, a controller can electrically connect or disconnect particularresonant circuits from a particular LNA.

The first signal is provided to the first LNA at block 812 to obtain afirst amplified signal. Similarly, the second signal is provided to thesecond LNA at block 814 to obtain a second amplified signal. Further, atthe block 812, the resonant circuit in electrical communication with thefirst LNA filters out components of the first amplified signalassociated with the second communication band. Similarly, at the block814, the resonant circuit in electrical communication with the secondLNA filters out components of the second amplified signal associatedwith the first communication band.

The first amplified signal and the second amplified signal may becombined at the block 816. Combining the amplified signals may includecombining the filtered versions of the amplified signals. Moreover, incertain embodiments, combining the amplified signals may include usingan impedance matching network 302 to match the impedance between thecommunication path of the first signal and the communication path of thesecond signal. In addition, the impedance matching network may match theimpedance of the two communication paths to an output line that providedthe aggregated signal to, for example, the transceiver 104.

In certain embodiments, the process 800 can include processing a singleband signal. In such cases, the LNA associated with the bandwidth of thereceived signal may be disconnected from its corresponding resonantcircuit. Alternatively, the corresponding resonant circuit may beconfigured in a bypass mode that allows the signal to pass throughwithout filtering the amplified signal received from the LNA.

Terminology

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” The term “coupled” is used to refer tothe connection between two elements, the term refers to two or moreelements that may be either directly connected, or connected by way ofone or more intermediate elements. Additionally, the words “herein,”“above,” “below,” and words of similar import, when used in thisapplication, shall refer to this application as a whole and not to anyparticular portions of this application. Where the context permits,words in the above Detailed Description using the singular or pluralnumber may also include the plural or singular number respectively. Theword “or” in reference to a list of two or more items, that word coversall of the following interpretations of the word: any of the items inthe list, all of the items in the list, and any combination of the itemsin the list.

The above detailed description of embodiments of the inventions are notintended to be exhaustive or to limit the inventions to the precise formdisclosed above. While specific embodiments of, and examples for, theinventions are described above for illustrative purposes, variousequivalent modifications are possible within the scope of theinventions, as those skilled in the relevant art will recognize. Forexample, while processes or blocks are presented in a given order,alternative embodiments may perform routines having steps, or employsystems having blocks, in a different order, and some processes orblocks may be deleted, moved, added, subdivided, combined, and/ormodified. Each of these processes or blocks may be implemented in avariety of different ways. Also, while processes or blocks are at timesshown as being performed in series, these processes or blocks mayinstead be performed in parallel, or may be performed at differenttimes.

The teachings of the inventions provided herein can be applied to othersystems, not necessarily the system described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments.

Conditional language used herein, such as, among others, “can,” “might,”“may,” “e.g.,” and the like, unless specifically stated otherwise, orotherwise understood within the context as used, is generally intendedto convey that certain embodiments include, while other embodiments donot include, certain features, elements and/or states. Thus, suchconditional language is not generally intended to imply that features,elements and/or states are in any way required for one or moreembodiments or that one or more embodiments necessarily include logicfor deciding, with or without author input or prompting, whether thesefeatures, elements and/or states are included or are to be performed inany particular embodiment.

Disjunctive language such as the phrase “at least one of X, Y, or Z,”unless specifically stated otherwise, is otherwise understood with thecontext as used in general to present that an item, term, etc., may beeither X, Y, or Z, or any combination thereof (e.g., X, Y, and/or Z).Thus, such disjunctive language is not generally intended to, and shouldnot, imply that certain embodiments require at least one of X, at leastone of Y, or at least one of Z to each be present.

Unless otherwise explicitly stated, articles such as “a” or “an” shouldgenerally be interpreted to include one or more described items.Accordingly, phrases such as “a device configured to” are intended toinclude one or more recited devices. Such one or more recited devicescan also be collectively configured to carry out the stated recitations.For example, “a processor configured to carry out recitations A, B andC” can include a first processor configured to carry out recitation Aworking in conjunction with a second processor configured to carry outrecitations B and C.

While certain embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the disclosure. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms; furthermore, various omissions, substitutions and changes in theform of the methods and systems described herein may be made withoutdeparting from the spirit of the disclosure. The accompanying claims andtheir equivalents are intended to cover such forms or modifications aswould fall within the scope and spirit of the disclosure.

What is claimed is:
 1. A method of processing a multiband signal, themethod comprising: receiving a multiband signal at an antenna of awireless device; filtering the multiband signal using a plurality ofbandpass filters to obtain a first signal and a second signal;determining the first bandwidth of the first signal and the secondbandwidth of the second signal; amplifying the first signal to obtain afirst amplified signal; configuring a first resonant circuit to filterfirst noise associated with the second bandwidth from the firstamplified signal; filtering the first noise from the first amplifiedsignal using the first resonant circuit to obtain a first filteredamplified signal; amplifying the second signal to obtain a secondamplified signal; configuring a second resonant circuit to filter secondnoise associated with the first bandwidth from the second amplifiedsignal; filtering the second noise from the second amplified signalusing the resonant circuit to obtain a second filtered amplified signal;and combining the first filtered amplified signal and the secondfiltered amplified signal.
 2. The method of claim 1 wherein configuringthe first resonant circuit includes configuring a set of switchedcapacitors based on the second bandwidth.
 3. The method of claim 1wherein the first signal is amplified using a first low noise amplifierand the second signal is amplified using a second low noise amplifier.4. An integrous signal combiner comprising: a first low noise amplifierconfigured to process a first receive signal of a first bandwidth toobtain a first amplified receive signal; a second low noise amplifierconfigured to process a second receive signal of a second bandwidth toobtain a second amplified receive signal; a first resonant circuit inelectrical communication with the first low noise amplifier, the firstresonant circuit dynamically configurable to filter noise within thefirst amplified receive signal corresponding to at least the secondbandwidth based at least in part on a frequency value of the secondbandwidth; a second resonant circuit in electrical communication withthe second low noise amplifier, the second resonant circuit dynamicallyconfigurable to filter noise within the second amplified receive signalcorresponding to at least the first bandwidth based at least in part ona frequency value of the first bandwidth; and a controller configured todynamically configure the first resonant circuit by modifying aconfiguration of a first set of switched capacitors based at least inpart on a determination of the frequency value of the second bandwidthand to dynamically configure the second resonant circuit by modifying aconfiguration of a second set of switched capacitors based at least inpart on a determination of the frequency value of the first bandwidth.5. The integrous signal combiner of claim 4 wherein the first resonantcircuit is further configurable to operate in a bypass mode.
 6. Theintegrous signal combiner of claim 4 further comprising a combinerconfigured to combine at least the first amplified receive signal andthe second amplified receive signal.
 7. The integrous signal combiner ofclaim 4 further comprising an impedance matching network configured to:match the impedance of at least the first resonant circuit and thesecond resonant circuit; and combine at least the first amplifiedreceive signal and the second amplified receive signal.
 8. The integroussignal combiner of claim 4 further comprising a third LNA configured toprocess a third receive signal of a third bandwidth to obtain a thirdamplified receive signal.
 9. The integrous signal combiner of claim 8further comprising a third resonant circuit in electrical communicationwith the third low noise amplifier, the third resonant circuitconfigurable to filter noise within the third amplified receive signalcorresponding to at least one of the first bandwidth or the secondbandwidth.
 10. The integrous signal combiner of claim 8 wherein thethird low noise amplifier is not in electrical communication with aresonant circuit.
 11. The integrous signal combiner of claim 8 whereinthe third low noise amplifier is further configured to provide the thirdamplified receive signal to a transceiver without filtering noise withinthe third amplified receive signal corresponding to at least one of thefirst bandwidth or the second bandwidth.
 12. The integrous signalcombiner of claim 8 wherein at least one of the first low noiseamplifier, the second low noise amplifier, or the third low noiseamplifier is configured to be inactive while at least one other lownoise amplifier of the first low noise amplifier, the second low noiseamplifier, or the third low noise amplifier is configured to be active.13. The integrous signal combiner of claim 4 wherein the first resonantcircuit includes a first filter and the second resonant circuit includesa second filter.
 14. The integrous signal combiner of claim 4 whereinthe first resonant circuit includes the first set of switched capacitorsand the second resonant circuit includes the second set of switchedcapacitors.
 15. A front-end module comprising: an integrous signalcombiner including a first low noise amplifier configured to process afirst receive signal of a first bandwidth to obtain a first amplifiedreceive signal, a second low noise amplifier configured to process asecond receive signal of a second bandwidth to obtain a second amplifiedreceive signal, a first resonant circuit in electrical communicationwith the first low noise amplifier, the first resonant circuitdynamically configurable to filter noise within the first amplifiedreceive signal corresponding to at least the second bandwidth based atleast in part on a frequency value of the second bandwidth, a secondresonant circuit in electrical communication with the second low noiseamplifier, the second resonant circuit dynamically configurable tofilter noise within the second amplified receive signal corresponding toat least the first bandwidth based at least in part on a frequency valueof the first bandwidth, and a controller configured to dynamicallyconfigure the first resonant circuit by modifying a configuration of aconfigurable element based at least in part on a determination of thefrequency value of the second bandwidth; and an impedance matchingnetwork in communication with the integrous signal combiner andconfigured to match the impedance of at least the first resonant circuitand the second resonant circuit.
 16. The front-end module of claim 15wherein the impedance matching network is further configured to combineat least the first amplified signal and the second amplified signal. 17.The front-end module of claim 15 wherein the first resonant circuit isfurther configurable to operate in a bypass mode.
 18. The front-endmodule of claim 15 wherein the first resonant circuit includes theconfigurable element enabling the integrous signal combiner to bedynamically tuned.